Magnetic drive agitator



P 1951 G. J. OKULITCH EI'AL 2,566,743

MAGNETIC DRIVE AGITATOR Filed 001;. 24, 1949 INvsNTOHS GE GRGE JOSEPH OKULJTCH IGOR Z 02 UL! N ATTORNEY Patented Sept. 4, 1951 UNITED STATES PATENT OFFICE MAGNETIC DRIVE AGITATOR George Joseph Okulitch and Igor Zozulin, Vancouver, British Columbia, Canada Application October 24, 1949, Serial No. 123,176

A 4 Claims. 1

Our invention relates to improvements in magnetic drive agitators.

The objects of the invention are to provide an agitator capable of being driven inside a tank or vessel from a source of power outside said vessel wherein no mechanical connection is made between the source of power and the agitator; to provide means whereby every part of the agitating element within the vessel may be removed for cleaning and sterilizing with ease and dispatch; to provide a thin diaphragm in the wall of the vessel for supporting the agitating assembly whereby the drive between the driving element and the agitating assembly is magnetic so that the magnets of one of said parts and the magnetic material attracted by said magnets may be set in close proximity to each other to the end that the magnetic attractive force may be utilized to an optimum degree.

A further object is to provide means whereby an overload on the agitator will withdraw the driving element from operating position.

A still further object is to provide means whereby the agitator cannot be rotated through its magnetic drive until the drive rotor is reset by manual means.

Other objects will appear as the specification proceeds.

Referring to the drawings:

Figure 1 indicates a longitudinal sectional view of the invention mounted upon a wall of a vessel.

Figure 2 is a diagrammatic view of an electrical circuit.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral l indicates generally a tank or vessel for fluid to be agitated by the invention, and 2 is an end wall upon which the device is carried. For the purposes of description inner end when applied to a horizontal part will indicate that portion projecting towards the interior of the tank, or to the left of Figur l, and outer end will indicate that portion projecting to the right of the figure.

An annular flange 4 is fitted into an appropriate opening formed in the wall 2 of the tank which is adapted to support a removable housing 5.

A thin diaphragm I is secured to the inner face of the flange 4 which i apertured concentrically to receive the shoulder 8 of the agitator shaft 9. A washer I is used as a stiffener for the inner portion of the diaphragm 1 and is secured thereto by a weld line about its periphery. This washer also serves to support the shaft 9.

The shaft 9 is provided with a threaded shoulder l2 which is adapted to be engaged by the free end of a bushing [4 having an inturned end l5 for the purpose of retaining a thrust bearing ball I6.

Freely mounted upon the bushing l4 of the shaft 9 is a sleeve I! having an end closure [9 which normally bears against the ball [6. The end closure I8 is apertured as at 20 and lubrication grooves 2| as indicated in dotted line lead from the apertures 29 to discharge adjacent the diaphragm 7. An apertured disc 22 supports a rim 23 in which is embedded a plurality of permanent magnets 24 to form a driven rotor 25. The inner end of the sleeve is provided with an impellor or agitator 21 of an appropriate type, which is adapted to exert a thrust to the liquid within the tank away from the diaphragm I so that the rotor sleeve ll remains in place upon the bushing 14 without requiring any fastening means.

A shaft member 30 consisting of a circular boss 3! having a flange 32 at its inner end and a drive rotor shaft 34 is aligned with the shaft 9 and is connected to the threaded end 35 of the agitator shaft 9.

A bushing 38 is fitted upon the drive rotor shaft and fitted upon said bushing is th hub 39 of a drive rotor 40, the bushing being preferably a press fit in the hub to enable the hub and bushing to slide endwise of the shaft 34.

The hub 39 is provided with an apertured disc 42 having a hollow rim 43 in which a plurality of permanent horseshoe magnets 44 are inserted.

By virtue of the drive and driven rotors their journalling shafts and mountings being carried by a thin membrane or diaphragm I, the magnets 24 and 44 can be set with their poles very closely spaced apart, consequently the effective work done by the magnets 44 in moving the magnets 24 about their orbit is high.

The rotor hub 39 is provided with a thrust bearing 46 and interposed between the inner end of the hub and the flange 32 of the shaft member 30 is a compression spring 4! which is of sufiicient strength to force the drive rotor outwardly or to the right when the several magnets 44 of the driv rotor become disallgned from the coacting magnets 24 of the driven rotor 25 for a substantial interval of time, as for instance, if an overload develops on the driven rotor so that each magnet of the drive rotor reaches a position where its poles are directly opposite like poles of corresponding magnets of the driven rotor, then the repulsion of the said magnets 44 and 24, plus the force of the spring 41, will force the drive rotor 40 away from the diaphragm, so that no magnetic drive will then be imparted to the driven rotor 25.

The drive rotor shaft 3 3 extends through the end wall 49 of the housing and is externally threaded as at 50.

Nuts 51 and 52 are fitted upon the shaft 34 inside and outside of the wall as respectively and are so adjusted as to support the centre of the diaphragm l and maintain the pole pieces of the magnets of the drive and driven rotors 4E! and 25 equidistant from adjacent annulus of said diaphragm. By adjustably supporting the diaphragm as above described, free running of the rotors is assured and a minimum spacing between drive and driven rotor magnets may be maintained and diaphragm deflection incidental to thrust of the agitator and static head of fluid in the tank is entirely prevented.

A threaded end of the shaft 34 is bored to receive a plunger 55 which is provided with a hand knob 55 at its outer end and a cross pin 56 adjacent its inner end which extends through opposed slots 51 formed in said shaft. The plunger 554i is normally held in outwardly extended position by means of a compression spring 59 housed within the shaft and the cross pin is adapted to engage the end of the rotor 4i] when the plunger is thrust inwardly to restore the magnets ti l into effective attractive position relative to the magnets .24.

A gear wheel El is fitted upon the hub 33 to rotate it from a driven pinion 82 which is secured upon a shaft 63 extending through the end wall 39 of the housing 5. This shaft is adapted to be driven from a motor 65 shown only in the diagram of Figure 2 and controlled by a circuit shown in the diagram of Figure 2.

A switch box it is fitted in a wall of the housing 5 and encloses a circuit breaker C having a push button il extendin through the box wall into the housing 5.

In the housing adjacent the switch box is a pivotally mounted arm 73 having a transverse adjusting screw "M adapted to bear upon the button ll when the free end 76 of the arm is moved outwardly or to the right of the Figure 1 in re sponse to a similar movement of the drive rotor, which causes a face of the driven gear 6| to engage said arm is.

The motor 65 used in driving the agitator is three phase and the circuit includes three main leads 8?), 8!, and 82, the lead 32 being the neutral wire. A triple pole or master switch 8 controls each of the leads 8G, 8! and .32 simultaneously.

The circuit breaker C consists of a normally closed double pole switch 86 and a normally open single pole switch 87 coupled for simultaneous operation. The switch 85 controls the leads 8G and '82, and the switch 8'! controls a red lamp 88 connected between the leads BI and 82 beyond the master switch 84.

A second triple pole switch 90 controls the leads B3 and to the motor and also a green lamp 92 connected in parallel between leads 82 and A white lamp 9 is connected in series in the lead beyond the circuit breaker C and a resistor 35 is also connected in series with said lead 89 beyond said circuit breaker.

A second resistor 9.? is connected in series in 4 the lead 82 beyond the circuit breaker C. These two resistors 95 and 9'! and the white lamp 94 bypass the second triple pole switch 90 when said switch is open.

The attraction between the magnets of the drive and driven rotors ill and 25 is suflicient to keep said rotors in close proximity to the diaphragm I and to impart rotation to the driven rotor from the drive rotor when the driven rotor is under normal load, but is insufiicient to overcome the counter thrust of the spring 41 if there is extensive lag in rotation of the driven rotor at over that of the drive rotor 40.

If the rotor 40 is brought to normal motor speed rapidly from rest it will overrun the driven rotor so that for a major interval of the time of rotation the magnets of one rotor will be circumferentially separated or out of step with those of the other rotor and the spring 41 will cause the rotor 40 to recede endwise of its shaft away from the diaphragm.

When both rotors are at rest, or when the drive motor is running slowly, the respective magnets can be brought in opposition to each other by thrusting the knob 55 inwardly to impart endwise movement to the rotor 40. This will enable the attraction of the magnets one to the other to be more effective, so that the drive rotor will remain in its working position in close proximity to the diaphragm i.

The device as shown is in position to be started with the agitator 2i in place upon its shaft and the rotor ii? advanced to operating position close to the diaphragm I and the fluid to be agitated in the tank.

The circuit breaker C will have its switch 86 closed and its switch 81 open. To set the device in normal motion the switch 84 is closed. This permits current to flow through the leads 80,, 81 and B2 to motor, but the potential through 82 is lowered by the resistor 9? and the potential through is lowered by the resistor 9E and the white lamp 94, which latter will be illuminated incidental to the surge of current to the motor in overcoming its initial inertia. As this surge drops the resistor will pass the required potential and allow the white lamp to go out.

During this interval the motor will be gathering speed and the magnets of the drive rotor 40 will each be drawing a magnet of the driven rotor about its orbit so that both rotors will be rotating in unison.

As soon as the white light goes out the triple pole switch 98 is closed so that the current now flows directly through the full length of the leads 8E) and 22, and also through 8| so that the motor immediately steps up to normal running speed.

Simultaneously with the closing of switch 93 the green lamp 92 is illuminated, indicating to the operator Normal operation.

The opening of the master switch 34 will break the entire circuit and stop the motor but will not cause the driven rotor to retract from the diaphragm.

If in normal operation, an overload or other mishap causes the driven rotor to get out of step with the drive rotor, the latter will retract from driving position under the influence of spring 4711, thus tripping the arm 13 and causing the switch 86 to open and the switch 8.? to close, thus shutting on the motor and illuminating the red lamp 88, thus indicating that the device requires attention.

With the motor stopped manually and it being desired to dismantle the agitator vfor cleaning, it

is first necessary to break the magnetic attraction between the rotors. This is done by closing the second triple pole switch 90, then closing the master switch 84 momentarily, which gives full current to the motor, causing it t rotate rapidly at full current, thus throwing the drive rotor out of step with its driven rotor and allowing the spring 47 to retract the driven rotor. The above frees the driven rotor which can then be lifted off its shaft 9 for cleaning, etc.

What we claim as our invention is:

1. A device for imparting rotation to an agi-= tator or th like comprising a drive rotor and a driven rotor mounted in axial alignment, permanent magnets regularly spaced about the periphery of one rotor and complementary pieces of magnetic material spaced about the other rotor, means for selectively rotating the drive rotor at a slow and at high speed, means for imparting endwise movement to one of the rotors to move it out of operative attraction from the other of said rotors when the rotation of said rotors is at substantial variance to each other, said endwise movement imparting means being of such magnitude as to overcome the operative attraction of the magnets when high speed rotation is imparted to a rotor while said rotor is at rest.

2. A device for imparting rotation to an agitator or the like comprising a drive rotor and a driven rotor mounted in axial alignment, permanent magnets regularly spaced about the periphery of one rotor and complementary pieces of magnetic material spaced about the other rotor, means for selectively rotating the drive rotor at a slow and at high speed, spring means for imparting endwise movement to one of the rotors to move it out of operative attraction from the other of said rotors when the rotation of said rotors is at substantial variance to each other, said spring means being of such force as to overcome the operative attraction of the magnets when high speed rotation is imparted to a rotor and said rotor is at rest, one of said rotors being endwise detachable subsequent to endwise movement of the other rotor from operative attraction position.

3. A device for imparting rotation to an agitator or the like comprising a drive rotor and a driven rotor mounted in axial alignment, permanent magnets regularly spaced about the periphery of one rotor and complementary pieces of magnetic material spaced about the other rotor, electromagnetic means for progressively rotating the drive rotor first at slow and then at high speed, and a manually controlled switch for applying said means at high speed to the drive rotor when at rest, and means operative in re=- sponse to rotation of one rotor at a substantially different rate of speed of th other rotor for moving one rotor endwise out of operative attraction from the other rotor.

4. A device for imparting rotation to an agitator or the like comprising a drive rotor and a driven rotor mounted in axial alignment, permanent magnets regularly spaced about the periphery of one rotor and complementary pieces of magnetic material spaced about the other rotor, means for imparting endwise movement to one rotor to move it out of operative attraction when one rotor is rotating at a substantially greater speed than the other, manual means for returning the endwise moved rotor to operative attractive position adjacent the other rotor, means for rotating one rotor and through it drive the second rotor at a slow and a high speed, and means for imparting such high speed to one rotor as to cause endwise movement of a rotor out of opera tive attraction to the other rotor.

GEORGE JOSEPH OKULITCH. IGOR ZOZULIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,404,745 Donauer Jan. 31, 1922 1,954,014 Lipman Apr. 10, 1934 2,230,717 De Lancey 1 Feb. 4, 1941 2,386,505 Puchy Oct. 9, 1945 2,437,871 Wood May 16, 1948 2,481,172 Staggs Sept. 6, 1949 2,506,886 Okulitch May 9, 1950 

